Psychophysical scaling of stimulus similarity in 3-month-old infants and adults

The ability of 3-month-old infants to discriminate novel components of a prefamiliarized stimulus was assessed using an operant paradigm. Subjects were familiarized with the standard stimulus (five-component mobile) in three daily conditioning sessions and then were exposed to a comparison mobile containing from zero to four novel components substituted for familiar elements at the outset of a fourth daily session. Although a reliable reduction in mean number of footkicks was found only when an extreme number of components was substituted, log-log plots of infant response as a function of degree of novelty indicated that discriminability was described by a power function. Adult judgments of the similarity between the standard mobile and each degree of novelty were also described by a power function, suggesting a common basis may underlie the perception of similarity in the two groups. The finding of a power function for infant response to visual novelty is consistent with reports of similar discriminability functions in infant olfaction and audition. However, duration of visual fixation increased nondifferentially to all test stimuli, irrespective of degree of novelty. The latter finding is inconsistent with predictions arising from the visual attention literature.     

Factors affecting the acquisition and elimination of children's donating behavior

Thirty-five 6- to 10-year-old children with initial low rates of donating to help a peer either simply received a fine for each failure to donate (n = 7) or also were informed of the contingency between the fine and failure to donate (n = 28). Explanation of the contingency was necessary to increase children's donation rates. Donations continued at high rates during a gradual, unannounced removal of the fine contingency, but decreased when children were informed that fines were no longer in effect, particularly for children who had failed to donate at least once during training and had actually been fined. Overall, addition of a distraction or an inequity procedure did not reduce donating below rate reductions due to the announced extinction procedure alone.     

Environmental Influences on Aggression: The Effects of Darkness and Proximity of Victim

It was hypothesized that darkness acts as a disinhibitor, and that subjects would deliver higher intensity shocks to a victim in a dimly lit setting than in a brightly lit setting. It was also predicted that this effect would be greater when subject and victim were in close proximity than when they were isolated from each other. The results supported these predictions. It was suggested that lighting may have important effects on social behaviors, and that further research on the influences of lighting on human behavior is needed.     

Time discrimination training of laboratory animals using a PDP-8 computer

The purpose of this paper Is to describe the use of a small, general-purpose digital computer system in the training of laboratory animals to discriminate stimuli on the basis of their duration. The computer hardware and software required for such training, together with some illustrative results from two recent studies, will be described.     

A cryogenic implant for producing reversible functional brain lesions

This paper describes a permanently implanted device for applying cold to localized parts of the brain surface in order to produce reversible functional lesions in behaving animals. It consists of an array of several independently controlled stainless steel tubing loops, each shaped to fit a separate brain area. Cooled alcohol is pumped through the tubing and temperatures are monitored with attached thermocouples. Implanted loops can be cooled to 0°C within 15 sec, and temperatures can be maintained at ±1°C of accuracy. Tissue tolerance is excellent: Implants have been demonstrated to last up to 1 year or more. Methods and materials for construction are discussed.     

Effect of mutual acquaintance on the construction of conversation

In a previous investigation, we demonstrated the role of questions as an instructional resource in the social construction of conversation by depriving conversationalists of their use. The resulting conversational structure, measured in terms of the ability of third parties to reconstruct the dialogues after they had been randomized, was impaired. The importance of culturally shared knowledge for the reconstruction (and by implication the construction) task was apparent in the superiority of British over Canadian subjects in reconstructing unconstrained British dialogues. The present study was concerned with the effects of privately shared knowledge on the construction of conversation. Conversational structure and the frequency of questions were greater in strangers' than in mutual acquaintances' unconstrained dialogues. Strangers' dialogues, but not those of mutual acquaintances, were disrupted under a ban on questions. The results were taken to indicate that strangers need to provide one another with continual instruction in how to proceed, whereas mutual acquaintances, in virtue of their privately shared social knowledge, can construct orderly dialogue with less moment-to-moment guidance.     

Clothing: Communication, Compliance, and Choice

This study looks at some effects of five different styles of women's clothing: Formal Skirt, Formal Pants, Casual Skirt, Casual Pants, and Jeans. There were no significant differences in compliance to a request to fill out a questionnaire made by experimenters dressed in the five clothing styles, although experimenter age and sex effects were found. Ratings of photographs of the five dress styles indicate that a model was viewed by both male and female subjects as most happy, successful, feminine, interesting, attractive, intelligent, and wanted as a friend when wearing a Formal Skirt outfit and as least so when wearing Jeans. She was also seen as more active when wearing pants as compared with a skirt. Subjects' reasons for choosing what clothing to wear did not indicate that how one will appear to others is the major factor in clothing selection. It appears that clothing does communicate something about the wearer but may influence behavior toward her primarily in the absence of other information about her status.